Virtual Net Energy Metering (VNM) is a tariff arrangement that enables a multi-meter property owner to allocate a solar system's energy credits to other tenants. The VNM tariffs were first piloted under the CSI Multi-family Affordable Solar Housing Program (MASH) as a means of providing equal and direct benefits of the solar system to low income tenants in an affordable housing complex.
Based upon the merits of the pilot, the CPUC authorized the expansion of VNM to the general multi-tenant market in Decision (D.)11-07-031 (see section 4.0). This decision directed PG&E, SCE and SDG&E to file advice letters proposing VNM tariffs for general participant (non_MASH) eligibility, including proposed cost recovery for VNM billing..
On December 8, 2011, Energy Division Staff hosted a workshop at the CPUC to discuss issues pertaining to the proposed VNM general market tariffs. The Energy division will issue Proposed Resolutions in Q1 2012.
Historically, multi-tenant building with individual electric meters for each tenant faced difficulties installing distributed solar PV systems because of the problem of assigning the benefits of the generation to each occupant. A system could easily be connected to a common area load or to an individual tenant, but if it was connected directly to multiple loads, there would be no way of ensuring equitable distribution of the generation. Some tenants would benefit more than others. Installing multiple systems, one for each tenant or load in the building, is cost prohibitive.
Virtual Net Metering (VNM) allows MASH participants to install a single solar system to cover the electricity load of both common and tenant areas connected at the same service delivery point. The electricity does not flow directly to any tenant meter, but rather it feeds directly back onto the grid. The participating utility then allocates the kilowatt hours from the energy produced by the solar PV generating system to both the building owner's and tenants' individual utility accounts, based on a pre-arranged allocation agreement. The intent of VNM is to help low income multifamily residents receive direct benefits of the building's solar system, rather than all of the benefits going to the building owner. For more information, please contact the MASH Program Administrator for your utility service territory, or click on the links below to go to the MASH VNM pilot tariffs: